Background

Introduction

I am a Principal Investigator in cardiovascular sciences, based at the Institute of Genetic Medicine, and have a cardiac surgical practice that focusses on surgery of the aortic valve and aorta. My research interests include cardiac regeneration and fibrosis, the mechanisms underlying thoracic aortic aneurysms and, in the clinical field, minimally invasive cardiac surgery and aortic valve surgery.

Esteem indicators

Research

Cardiac regeneration

Until
recently the adult mammalian heart was considered to be a post-mitotic organ,
lacking native stem cells and incapable of self-repair. This view is
being increasingly challenged, and a number of groups have isolated populations
of putative cardiac stem cells and/or demonstrated evidence of
cardiomycoyte replication.

We have used the expression of telomerase, an
enzyme that maintains the ends of telomeres in dividing cells, protecting them
from long-term senescence, to test the hypothesis that native cardiac stem
cells can be identified by telomerase expression, thereby identifying them
using a functional, rather than antigenic, marker.

The numbers of telomerase expressing cells present
in the heart appears to decrease with age and very few are found in the adult
mammalian heart, but we have observed the appearance of increased numbers in
the heart muscle surrounding areas of damage or at times of increased
growth. We are now exploring their role in myocardial disease and
regeneration.

More
recently we have, in collaboration with the Neuromuscular Research group at the
Institute of Genetic Medicine, demonstrated cardiac regeneration in models of
cardiomypoathy and are currently undertaking work, funded by the BHF, to
explore this further.

Cardiac fibrosis

Almost all cardiac disease is associated with some degree of abnormal cardiac fibrosis, the presence and degree of fibrosis often given an indirect indication of the severity of the underlying condition, correlating with symptoms and prognosis and in some conditions influencing the likelihood of successful treatments. In collaboration with the Fibrosis Group at the Institute of Cellular Medicine, we are investigating the signalling pathways underlying cardiac fibrosis, with a focus on serotonergic signalling.

Aortic valve surgery

Open heart surgery to replace the aortic valve is one of the most frequently performed cardiac surgical procedures. It is usually performed through a median sternotomy incision, which involves division of the entire breast bone. More recently a procedure has been developed to perform this through a smaller incision, limited to the manubrium (the upper part of the breast bone). Early results have suggested that patients undergoing the surgery through the smaller incisions have reduced blood loss and a reduced need for blood transfusion. We are now undertaking an NIHR-funded research project (MAVRIC) randomising patients to either conventional or manubrium-limited sternotomy to compare blood loss, transfusion requirements and speed of recovery from surgery.